Sprite Atlas Packer

Every separate image a game draws costs the graphics card a change of texture. Packing many sprites into one image, the atlas, lets the engine draw them together, which runs faster and loads quicker than a hundred small files.

The packer fits sprites of different sizes together like a jigsaw, largest first, and writes down where each one ended up. Sprites are never rotated or scaled, so they look exactly as you drew them.

• Padding: 1 or 2 clear pixels between sprites stop one sprite’s edge from showing on its neighbour when the texture is scaled or filtered.
• Trim empty edges: leaves out the clear border around each sprite. The data file records how much was removed, so the sprite still sits where it did.
• Power-of-two size: rounds the sheet up to 256, 512, 1024 and so on. Modern engines rarely need it; some mobile and web targets still prefer it.
• Names: each sprite is named after its file, without the extension, so name the files the way you want to refer to them in code.

JSON, frames by name is the layout TexturePacker made common. Phaser and PixiJS load it directly, and importers exist for Godot, GameMaker and most other engines. JSON, list of frames holds the same data as an ordered list.

Godot (.tres) writes one AtlasTexture file per sprite, named after it. Copy them into your project in one folder with the PNG and use any of them as a texture, on a Sprite2D for example. No importer plugin is needed, and trimmed sprites keep their original size.

Unity (.png.meta) is Unity’s own import file. Copy it into the project beside the PNG and the texture arrives sliced into named sprites, with point filtering and no compression, as pixel art needs.